Automotive OEMs (original equipment manufacturers) typically require an electrical system (e.g., a battery and associated key-off loads drawing battery power) of a vehicle to be configured in a manner for allowing the vehicle to be started after it has been static for up to 30 days (i.e., 30-day ready-to-start performance). Design targets for best-in-class performance assume a static KOL (key-off-load) of less than 15 mA (milli-amps). Unfortunately, a vehicle with an electrical system having a considerable number of KOLs and/or power intensive KOLs can have a KOL need of 20 mA to 30 mA. This being the case, it can be a challenge to maintain a minimum acceptable SOC (state of charge) for a battery of such a vehicle.
Known solutions for achieving 30-day ready-to-start performance often drive added cost to a vehicle, reduced feature content capability, and/or shedding of electrical loads over the 30-day period. It is well known that shedding of electrical loads can cause certain systems to appear to be malfunctioning, which can result in TGW (Things-Gone-Wrong) demerits to an OEM of the vehicle, adverse customer satisfaction ratings, and/or increased warranty clams if parts are replaced.
During slow sales periods, lot storage times can exceed 30 days at the OEM's manufacturing site, dealer sales/storage lots, or a combination of both. During these slow sales periods or for vehicles being shipped long distances, static storage time needs of OEMs can often be as much as 120 days or greater. As such, solutions for achieving over 120 days of ready-to-start performance require shedding almost all KOLs and dropping the 15 mA static 30-day KOL target to zero or near zero. This ultra low level of KOL will naturally result in higher levels of TGWs and warranty risk for a 120-day ready-to-start system relative to issues experienced with a 30-day ready-to-start system due to the need to completely disconnect all high KOL systems and the resulting loss of total feature/function.
Various approaches for enhancing 30-day ready-to-start performance are known. To enhance their effectiveness and/or practicality, minor improvements in KOL can be achieved by zero cost methods such as reduced scan rates for radio frequency (RF) receivers and digital input/output (I/O) signals. However, these types of improvement approaches offer only minor KOL reduction (e.g., 100-200 uA) and create the risk of TGWs and warranty for affected systems (e.g., remote entry, alarms, tire pressure sensing, and others). Furthermore, such known approaches for enhancing 30-day ready-to-start performance are also known to have certain shortcomings that limit their effectiveness and/or practicality with regard to cost, weight, and/or vehicle modularity (i.e., use across multiple models of vehicles).
One such approach for enhancing 30-day ready-to-start performance relates to use of a larger battery for enhancing 30-day ready-to-start performance, which can add cost (e.g., as much as $10, per vehicle) and/or weight, (e.g., as much as 10 lbs per vehicle). Another such approach for enhancing 30-day ready-to-start performance relates to automated load shedding via semiconductor switches in a vehicle that has only one Hot At All Times (HAAT) power feed and having a Bipolar or FET switch (pass circuit) to fully activate the module for normal RUN operation. Implementation of such semiconductor switched load shedding is possible through use of circuits capable of being selectively switched off (e.g., via a network message) to lower KOL. However, this type of automated load shedding can add cost (e.g., as much as $1 to every effected module needing a robust protected pass circuit) and/or increase the potential for TGW demerits and warranty risks. Another such approach for enhancing 30-day ready-to-start performance relates to automated load shedding using a latching relay rather than a conventional relay because the relay and control circuit cannot draw any power after it switches the desired loads open circuit. The latching relay needs to be scaled for the total normal RUN current expected from the effected modules because the module KOL power feed is typically also the same feed used for RUN current consumption. Such a latching relay and control circuit can add cost (e.g., as much as $4 per vehicle) and/or increase the potential for TGW demerits and warranty repairs. Another such approach for enhancing 30-day ready-to-start performance relates to removable bus bars. But, their associated install/removal labor costs, the fixed cost of the bus bar/associated fuse socket, and/or issues adversely affecting vehicle modularity make them an undesirable solution. Yet another such approach for enhancing 30-day ready-to-start performance relates to reducing KOL by use of low quiescent regulators and other low power semiconductor devices, which can add cost (e.g., as much as $0.25 or more per device).
Various known aftermarket (A/M) remote start systems offer the capability of starting a vehicle's engine if the ambient temperature drops below a certain threshold and, optionally, if the vehicle battery falls below a certain voltage. However, there are several shortcomings associated with use of such known A/M remote start systems for managing SOC of the vehicle's battery. Because the primary function of A/M remote starter systems is to precondition a passenger cabin for comfort, one such shortcoming is that these remote start systems are not optimized or intended to reduce power consumption during such cabin temperature preconditioning (e.g., the air conditioning compressor and/or the blower fan are typically operated at maximum performance). Another such shortcoming is that these add-on remote start systems do not have access or ability to control all vehicle systems to aggressively minimize power demand of these vehicle systems during the remote start operation. Another such shortcoming is that, due mainly to emissions concerns, these remote start systems do not have provisions for causing the vehicle's engine to run at an idle level that is significantly higher than a target idle (e.g., higher idle than the idle during regular operation of the engine) or for extended periods as needed to properly charge the battery. Another such shortcoming is that these remote start systems can create a risk of a fire (e.g., from catalyst or exhaust heat when parked over dry vegetation). Still another such shortcoming is that, under the assumptions that the risk of a no-start condition due to lack of fuel is of a higher severity than a cabin that is too hot or too cold, these remote start systems are configured to cease operation if a low fuel level condition is exhibited (e.g., a fuel level that would be typical of that of a new vehicle at an OEM's manufacturing site or dealer sales/storage lot). Still another such shortcoming is that such remote start systems cannot implement desired measures to ensure vehicle security. Yet another such shortcoming is that such remote start systems that offer a simple vehicle start when the battery is low or cold require the customer to incur the cost of the complete system including components not required for implementing only a vehicle battery charge event (e.g., radio frequency receiver, antenna, control fobs, etc).
Therefore, providing a battery charge event in a manner that overcomes shortcomings associated with known remote start systems and with known approaches for enhancing ready-to-start performance would be advantageous, desirable and useful.